论文部分内容阅读
使用隐式大涡模拟方法,研究传统球锥外形、幂次率外形以及冯·卡门外形3种母线形状对整流罩外壁面脉动压力环境的影响。研究结果表明:在跨声速条件下,3种外形都在折角区域产生激波/分离泡干扰现象,从而产生脉动压力的峰值,且峰值位置与时均激波位置基本一致;幂次率外形与冯·卡门外形能够显著减缓该区域的脉动压力环境,均方根脉动压力的极值比传统球锥外形低17%;由于分离点位置前后移动,使得母线折点与分离点之间的流动速度变化剧烈,同样会引起脉动压力的峰值,而冯·卡门母线在折点处过渡均匀,膨胀加速效应较弱,峰值并不显著。通过瞬时流场涡结构以及声压级频谱分析可知:传统球锥外形在折角之前的锥面区域湍流发展较慢,声压级要低于幂次率与冯卡门外形;分离再附后,传统球锥外形涡结构发展迅速,声压级比其他两种外形高出10 d B左右。
Implicit large eddy simulation method is used to study the influence of the traditional conical shape, the power rate profile and Von Karman profile on the pulsating pressure environment on the outer wall of fairing. The results show that all the three shapes have the shock / bubble separation disturbance in the folded corner region under the transonic condition, resulting in the peak value of the pulsating pressure, and the peak position is basically consistent with the location of the time-averaged shock wave. Von Carmen shape can significantly reduce the pulsating pressure environment in this area. The root-mean-square pulsating pressure extremum is 17% lower than that of the traditional conical shape. Because the separation point moves back and forth, the flow velocity between the break point and the separation point Variations, the same will cause the peak pressure pulsation, and von Karman bus transition at the break point, expansion acceleration effect is weak, the peak is not significant. According to the instantaneous flow field vortex structure and the spectrum analysis of sound pressure level, it can be seen that the turbulent flow in the conical surface of the traditional ball cone shape is slower than that of the von Karman shape in the cone angle, and the traditional Spherical cone vortex structure developed rapidly, the sound pressure level higher than the other two profiles about 10 d B.